To the Editor: The study by Dr Page and colleagues1 reported on the differential effects of fructose and glucose on cerebral blood flow in brain regions associated with appetite and reward pathways. I am concerned about several issues that could compromise the significance and applicability of these data.

One issue that the authors failed to address was that little if any fructose escapes the liver to become available to peripheral tissues.2 The peak level of plasma fructose after ingestion of a 75-g fructose drink in the study by Page and colleagues was just 5.6 mg/dL (Table 2 in article; a total peak increase of only 5.6 mg/dL).